package com.app.oasystem.controller;


import com.app.oasystem.constant.StaticParam;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

@WebServlet(name = "imageCodeController", urlPatterns = "/servlet/imageRandServlet")
public class ImageCodeController extends HttpServlet {
    private static final long serialVersionUID = -8886909847238030457L;

    private static final int INT_155 = 155;

    private static final int INT_4 = 4;

    private static final int INT_255 = 255;

    /**
     * 初始化
     */
    @Override
    public void init() throws ServletException
    {

    }

    /**
     * 处理GET方法
     */
    @Override
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
    {
        try {
            response.setHeader("Pragma", "No-cache");
            response.setHeader("Cache-Control", "no-cache");
            response.setDateHeader("Expires", 0);
            int width = 60, height = 20;
            BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            OutputStream os = response.getOutputStream();
            Graphics g = image.getGraphics();
            Random random = new Random();
            g.setColor(getRandColor(200, 250));
            g.fillRect(0, 0, width, height);
            g.setFont(new Font("Arial", Font.PLAIN, 18));
            g.setColor(getRandColor(160, 200));
            for (int i = 0; i < INT_155; i++) {
                int x = random.nextInt(width);
                int y = random.nextInt(height);
                int xl = random.nextInt(12);
                int yl = random.nextInt(12);
                g.drawLine(x, y, x + xl, y + yl);
            }
            String sRand = "";
            for (int j = 0; j < INT_4; j++) {
                String rand = String.valueOf(random.nextInt(10));
                sRand += rand;
                g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
                g.drawString(rand, 13 * j + 6, 16);
            }
            request.getSession().setAttribute(StaticParam.SESSIONKEY_IDENTIFYING_CODE, sRand);
            g.dispose();
            ImageIO.write(image, "JPEG", os);
            os.flush();
            os.close();
            os = null;
            response.flushBuffer();
        } catch (IllegalStateException e) {
            e.printStackTrace();
        }
    }

    /**
     * 处理POST请求
     */
    @Override
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

    /**
     * 注销
     */
    @Override
    public void destroy() {

    }

    public Color getRandColor(int fc, int bc) {
        Random random = new Random();
        if (fc > INT_255) {
            fc = 255;
        }
        if (bc > INT_255) {
            bc = 255;
        }
        int r = fc + random.nextInt(bc - fc);
        int g = fc + random.nextInt(bc - fc);
        int b = fc + random.nextInt(bc - fc);
        return new Color(r, g, b);
    }


}

